Balancing an unstable grid: The global COVID-19 crisis tests power network operators

Shifts in power demand patterns due to the COVID-19 crisis, combined with the growing penetration of intermittent and distributed generation globally, are complicating the management of some power networks. In response, grid operators—or governments on their behalf—have taken significant measures to expand their control of power grids in the name of reliability.[1]

IHS Markit recently published a report examining some measures taken to stabilize power grids in the face of COVID-19, and discussing what these actions may foretell about future network operations when intermittent and distributed generation satisfy larger shares of total demand.

Deferred maintenance on power system elements increases network operational risks during the coming months

A lot of nonessential planned maintenance has been postponed owing to challenges in staffing and sometimes in the shipment of spare parts and has at times been influenced by lowered revenues from ratepayers. Maintenance deferments on transmission and distribution lines and power plants have occurred in the United States, Spain, France, Russia, Iran, and New Zealand, to name just a few countries.

In many instances, large-scale maintenance has been rescheduled and bundled in the northern hemisphere's summer and the southern hemisphere's winter, rather than in the spring/fall shoulder seasons when temperatures are milder and loads less extreme. For example, Spain's transmission system operator (TSO) Red Eléctrica stated that some delayed routine outages would be rescheduled to the winter.

Increased load and supply forecast errors force some grid operators to take more actions to maintain reliability

The performance of grid operator forecasting and operational models is impacted by conditions that the pandemic has at times altered, notably load shapes, operating voltages, frequency levels, and transmission flows.

Prior to the crisis, grid operators relied on large industrial facilities to anchor their demand forecasts and help with reactive power support. But with some of these facilities now halted, operators must ramp up their actions to maintain network reliability. For example, the Dutch TSO TenneT faced an emergency in May from a voltage surcharge on its network, itself the result of low demand, high solar generation, and limited contracted reactive power.

An important question is whether electric loads will largely return to their pre-COVID-19 shapes, or not. It could take time for TSOs to comfortably forecast demand again.

Network adequacy concerns raised by COVID-19 highlight the need for new revenue schemes for balancing services

Faced with the challenges described above, many TSOs are seeking to improve their control of the grid through frequency, voltage and reactive power support, load shedding coordination, and other measures that better manage large connected power generators and offtakers.

Furthermore, important policy changes have been implemented or proposed for greater grid control. Among these, policy changes that give grid operators a greater say in which assets dispatch (or not) are instructive for a future with more renewables. For example, in the United Kingdom, rights were granted to the operator National Grid electricity ESO to disconnect production on the distribution system. In Mexico, the government granted the network operator CENACE the right to adjust dispatching rules and presented guidelines to provide new revenues for ancillary services.

Both intermittent and distributed generation can be a liability for network reliability, but coupled with modern grid technology they can become an asset

Wind and solar technologies can challenge the grid's operation because their generation is intermittent. However, these technologies are addressing some of these stability shortcomings during the COVID-19 crisis.

The operation of wind and solar units benefits from no refueling requirements and, in the case of solar, few moving parts. Furthermore, if coupled with grid equipment that allows network operators to curtail their generation, the proximity of distributed generation to demand centers or the ability of renewables to nearly immediately ramp down their output can be valuable capabilities to maintaining network reliability. For example, in Belgium, offshore wind units curtailed their generation in April to match lower demand needs when nuclear units did not.

Learn more about our global power research.

Etienne Gabel, a senior director at IHS Markit with the Latin America Gas, Power, and Energy Futures team, specializes in the analysis of regulatory and market developments in the natural gas and power sectors.

[1] For the purpose of this article, we use the term "grid operators" to cover the variety of entities worldwide that maintain power grids, whether from a physical standpoint or a market operations standpoint. These entities include independent system operators, transmission system operators, balancing authorities, state or regional utilities in charge of power networks, and more.

Posted 24 August 2020.

This article was published by S&P Global Commodity Insights and not by S&P Global Ratings, which is a separately managed division of S&P Global.